Safety lock for ladders



Aug. 23, 1966 J, ANTON, 5;; 3,268,195

SAFETY LOCK FOR LADDERS Filed Dec. 22, 1964 INVENTOR. JOHN ANTON JR.

BYGLWJIS A I'TOENEY5 United States Patent 3,268,196 SAFETY LOCK FOR LADDERS John Anton, Sr., 555 Oregon Ave., Clitfside, NJ. Filed Dec. 22, 1964, Ser. No. 420,329 3 Claims. (Cl. 248229) This invention refers to a safety lock for ladders and relates more particularly to a ladder clamp adapted to firmly connect the top of the ladder with the gutter at the edge of a roof.

Owners and inhabitants of one story or two story houses and homes are often required to use ladders in order to reach the roofs of their buildings. Statistics show that there is a substantial number of accidents which occur due to the sliding and dropping of a ladder which was leaned against the building. These accidents are caused by the shifting weight of the person climbing the ladder, by insufficiently firm support at the base of the ladder or by slippery wall surfaces.

An object of the present invention is to eliminate accidents of this nature through the provision of a ladder clamp of simple and inexpensive yet sturdy construction which will eifectively and firmly connect ladders used in connection with small houses of one or two stories with the roof gutter, so as to prevent any sliding movement of the ladder while it is in use, and which can be quickly and readily disassembled whenever necessary.

Other objects of the present invention will become apparent in the course of the following specification.

In the accomplishment of the objectives of the present invention it was found desirable to provide a safety lock for a ladder which is composed essentially of two clamps, namely, one clamp for firmly holding an edge of the roof gutter and another clamp for firmly and securely holding the top of the ladder, the two clamps being so constructed that they are readily adjustable to gutters and ladders of different sizes and constructions. Furthermore, the structures of the two clamps are so correlated that the user who has climbed on top of the ladder can quickly and easily manipulate both clamps with the least possible exertion of energy. A

The invention will appear more clearly from the following detailed description when taken in connection with the accompanying drawing showing by Way of example a preferred embodiment of the inventive idea.

In the drawing:

FIGURE 1 is a front view of a ladder safety lock constructed in accordance with the principles of the present invention.

FIGURE 2 is a top view of the lock.

FIGURE 3 is a side view.

FIGURE 4 is a rear view.

FIGURE 5 shows on a smaller scale a ladder leaning against a gutter and provided with a safety lock of the present invention.

The ladder safety lock shown in the drawing comprises a clamp for securing it to an edge of a gutter 11 and a clamp 12 for holding the top of a ladder 13 (FIG. 5).

The clamp 10 includes a threaded rod 14 which meshes with inner screw threads of a sleeve 15. The sleeve 15 through which the rod 14 extends, is located on top of a post 16. The outer end of the rod 14 carrier an elongated pin 17 which serves as a handle, so that the user by turning the pin 17 can quickly and easily move the rod 14 toward or away from another post 18 located opposite and spaced from the post 16. The end of the rod 14 facing the post 18 carries a cone-shaped clamping element 19 which is used to firmly engage the gutter 11 from one side. A plate 20 carried by the post 18 faces the clamping element 19 and is used to engage the opposite side of the gutter. The plate 20 may be made of metal but may be provided with a lining 21 of a plastic material, so as 3,268,196 Patented August 23, 1966 to make certain that the clamping of the gutter will not damage it in any way. The two vertical posts are joined by a lower horizontal bar 22, so that the bar 22 with the posts 16 and 18 constitute an upwardly extending U-shaped member. Obviously, the U-shaped member may be made of one piece and/or may be provided with outer strengthening plates to improve its rigidity.

The clamp 12 which is attached to the ladder, includes an elongated bracket 23 which is angularly U-shaped in transverse section, so that it is composed of a vertical portion 24 and upper and lower narrower horizontal portions forming projecting edges 25 and 26. The bracket 23 has open ends and it contains two clamping brackets 27 and 28 which are embraced by these edges and are of such size that they can conveniently slide without play within the bracket 23. The bracket 27 is located on the inside close to the portion 24 of the bracket 23, while the bracket 28 is located on top of the bracket 27. A transverse pin 29 is carried by the portions 25 and 26 of the bracket 23 close to one end of the bracket 23. The pin 29 is located a short distance from the bracket 27 and its purpose is to prevent the bracket 27 from falling out of the bracket 23. Another pin 30 extends through the portions 25 and 26 of the bracket 23 close to its other end and is located slightly above the bracket 28 so as to prevent it from falling out of the bracket 23. The length of each of the brackets 27 and 28 which is enclosed by the bracket 23, is about three quarters of that of the bracket 23. The bracket 27 has an outer end which is angularly U-shaped and which includes a portion 31 extending at right angles to the main longitudinal direction of the brackets, as well as a short end portion 32 extending parallel to this longitudinal direction. Thus the U- shaped end 31, 32 of the bracket 27 can be eifectively used to grasp and hold one side of the top of a ladder. The bracket 28 has a similar angular U-shaped outer end which includes a transverse portion 33 and an end portion 34 extending parallel to the longitudinal direction of the brackets, so that the ladder can be effectively grasped from the other side as well.

In accordance with the present invention, the device for firmly holding the brackets 27 and 28 in their clamped positions is also used as the means interconnecting the clamps 10 and 12. This device includes a connecting member 35 having a lower plate portion 36 extending in the longitudinal direction of the brackets and an upper U-shaped portion 37 having two prongs which extend in a plane perpendicular to that of the plate 36. The plate 36 fits in recesses provided in the outer edges of the horizontal portions 25 and 26 of the bracket 23. A screw 38 extends through an opening provided in the middle of the bracket 23. The clamping brackets 27 and 28 are provided close to their inner ends with elongated slots 39 and 40. The screw 38 extends through these slots. Thus the length of these slots determines the extent to which the outer U-shaped ends of the brackets 28 and 27 can be pulled out of the bracket 23. The screw 38 also passes through a hole provided in the plate 36 and carrier upon its outer end a winged nut 41 preferably provided with a washer.

It is apparent that when the nut 41 is loosened the user can conveniently pull out the U-shaped ends of the brackets 27 and 28 and then push them toward each other to clamp the top of the ladder. Then he can quickly turn the winged nut 41 to hold the brackets in place.

The connection between the gutter-engaging clamp 10 and the ladder-engaging clamp 12 is established by a screw 42 extending through a hole provided in the middle of the bar 22 which carries the posts 16 and 18. The screw 42 also extends between the prongs of the U-shaped upper support 37. The support 37 is firmly pressed against the bar 22 by a winged nut 43 carried upon the outer end of the screw 42.

It is apparent that after loosening the nut 43 the user can readily swing the bar 22 and thereby adjust the position of the clamp-carrying posts 16 and 18 relatively to the clamp-carrying bracket 23.

The operation of the ladder lock is apparent from the above description. The usual procedure is for the user to first climb up the ladder 13, then clamp the gutter 11 between the clamping element 19 and the plate 20 by manipulating the pin 17 of the rod 14, adjust if necessary the relative positions of the clamps by manipulating the nut 43 and finally clamp the top of the ladder by manipulating the clamping brackets 27 and 28 and the nut 41.

It is apparent that the example described above has been given solely by way of illustration and not by way of limitation and that it is subject to many variations and modifications within the scope of the present invention. All such variations and modifications are to be included within the scope of the present invention.

What is claimed is:

1. A lock for ladders, comprising in combination, a clamp for engaging a roof gutter, a clamp for engaging from both sides the top of a ladder, the second-mentioned clamp comprising an elongated bracket with projecting edges, two clamping brackets embraced by said edges and .slidable relatively to the first-mentioned bracket, each of said two clamping brackets having a separate angular end portion extending outside of the first-mentioned bracket, the angular end portions of the two clamping brackets extending toward each other, whereby said angular end portions may clamp the top of a ladder from opposite sides, said two clamping brackets having elongated slots, a screw extending through an opening in the first-mentioned bracket and through said slots, a connecting member having a lower plate portion through which said screw extends, a nut carried by said screw and adapted to press said plate portion against said two clamping brackets and said two clamping brackets against the first-mentioned bracket, said connecting member also having an upper portion; and means swingably connecting the first-mentioned clamp with the upper portion of said connecting member.

2. A lock in accordance with claim 1, comprising two pins carried by the projecting edges of the first-mentioned bracket adjacent opposite ends thereof, each of said pins being adapted to be engaged by a separate one of the two clamping brackets, thereby preventing said clamping brackets from falling out of the first-mentioned bracket.

3. A lock for ladders, comprising in combination, a clamp for engaging a roof gutter, said clamp comprising two posts, a threaded sleeve carried by one of said posts, a plate carried by the other one of said posts, a threaded r-od meshing with said threaded sleeve, whereby an edge of the roof gutter can be clamped between one end of said rod and said plate, a bar interconnecting said posts and a screw extending through said bar; another clamp for engaging from both sides the top of a ladder, the secondmentioned clamp comprising an elongated bracket with projecting edges, two clamping brackets embraced by said edges and slidable relatively to the first-mentioned bracket, each of said two clamping brackets having a separate angular end portion extending outside of the first-mentioned bracket, the angular end portions of the two clamping brackets extending toward each other, whereby said angular end portions may clamp the top of a ladder from opposite sides, said two clamping brackets having elonried by the first mentioned screw and adapted to press said prongs against said bar.

References Cited by the Examiner UNITED STATES PATENTS 2,663,484 12/1953 McPherson 182214 FOREIGN PATENTS 373 1/1906 Great Britain. 610,261 10/1948 Great Britain.

CLAUDE A. LE ROY, Primary Examiner.

I. F. FOSS, Assistant Examiner. 

1. A LOCK FOR LADDERS, COMPRISING IN COMBINATION, A CLAMP FOR ENGAGING A ROOF GUTTER, A CLAMP FOR ENGAGING FROM BOTH SIDES THE TOP OF A LADDER, THE SECOND-MENTIONED CLAMP COMPRISING AN ELONGATED BRACKET WITH PROJECTING EDGES, TWO CLAMPING BRACKETS EMBRACED BY SAID EDGES AND SLIDABLE RELATIVELY TO THE FIRST-MENTIONED BRACKET, EACH OF SAID TWO CLAMPING BRACKETS HAVING A SEPARATE ANGULAR END PORTION EXTENDING OUTSIDE OF THE FIRST-MENTIONED BRACKET, THE ANGULAR END PORTIONS OF THE TWO CLAMPING BRACKETS EXTENDING TOWARD EACH OTHER, WHEREBY SAID ANGULAR END PORTIONS MAY CLAMP THE TOP OF A LADDER FROM OPPOSITE SIDES, SAID TWO CLAMPING BRACKETS HAVING ELONGATED SLOTS, A SCREW EXTENDING THROUGH AN OPENING IN THE FIRST-MENTIONED BRACKET AND THROUGH SAID SLOTS, A CONNECTING MEMBER HAVING A LOWER PLATE PORTION THROUGH WHICH SAID SCREW EXTENDS, A NUT CARRIED BY SAID SCREW AND ADAPTED TO PRESS SAID PLATE PORTION AGAINST SAID TWO CLAMPING BRACKETS AND SAID TWO CLAMPING BRACKETS AGAINST THE FIRST-MENTIONED BRACKET, SAID CONNECTING MEMBER ALSO HAVING AN UPPER PORTION; AND MEANS SWINGABLY CONNECTING THE FIRST-MENTIONED CLAMP WITH THE UPPER PORTION OF SAID CONNECTING MEMBER. 